Shuttle-thread-replenishing mechanism.



P. F. DoRsEY. SHUTTLE THREAD REPLENISHING MEGHANISM.

l APPLICATION FILED JUNE 15, 1907. 1,07'74056, Patented Oct. 28 v1913 4 SHEETS-SHEET l.

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SHUTTLE THREAD REPLENISHING MEGHANISM.

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@is M l II/AV/ TNESSES P. F. DORSEY. l SHUTTLE THREAD RBPLENISHING MBGHANISM.

Patented 061:. 28, 1913.l

' mums-SEHEN.'

APPLIUAIION FILED JUNE 15, 1907..

UNITED srarus PATENT @Fortron FARNUM r. noRsEY, or NEWYORK, u. Y., Assreivonro BENJAMI'NPHILLIPSQ or i LYNN, MASSACHUSETTS.. H

sHU'r'rI.'u-THBEAD-Burr.entsinnev MCANISM.

To nl? '1c/10m 2'1 may concern:

e 1t` known that I, FARN UM F. DonsnY, a c1t1zen of thc lInited States, res1ding at New York, in the county of New York and Stateof New York, have invented certain new and useful Improvements in Shuttle-Thread Iteplenishing Mechanism; and I do hereby de'clare the following` to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to sewing machines and more especially to lock stitch sewing machines such as are adapted for use in the manufacture of'boots and shoes.

In this type of machine during each stitch 'forming operation the thread supply from which the locking thread is drawn passes through a loop of thread drawn through the work by the needle and the locking thread supply can thereftre contain but a limited quantity of thread. Consequently it is necessary to frequently suspend-the operation of the machine in order to replenish the supply vice which contains the locking thread supply with a. resulting loss of time and a reduction in the production of the machine.

Thereplenishing of the supply of thread in the shuttle or thread-holder when the supply. becomes exhausted has heretofore been performed by the operator who manually removes the empty thread bobbin and introduces a full bcbbin into theshuttle. or In accordance with the principal feature of the present invention the inconvenience and loss of time incident to the replenishing of the supply of thread in the thread-holder by the operator in the usual manner is eliminated by providing mechanism which operates to automatically introduce a supply of thread into the threadholder. In case ythe locking. thread supply is carried upon a thread bobbin as is usual, the loss of time incident to the'replenishmg of the thread Supply may `befurther reduced by also providing mechanism for automatically removing the empty bobbin from the thread-holder and the provision of such mechanisms constitutes a further-feature of the invention. 'i l v The provision of mechanism forr replenishingthe supply of thread in the thread- Aholder not only results in a reduction in the loss of time incident the vperformance of Specification of Letters Patent.

of thread in the shuttle 0r other (lethis operation and a consequentincre'ase in 1 rPatentedOct.28,1913. Application filed June 15,1907. Serial No'.379r,.263. I i` l ,l

the yproduction of the machine, but also en-` ables a reduction in the size of the threadholder. This is rendered practicable by reason of the facility with which the thread supply is replenished when exhausted and results in diminishing the length of the loop ofneedle thread which mustv be drawn thro-ugh the work and passed aroundithe -i thread-holder. Consequently there is less rendering of the thread back and forth through the work and about the threadhandling devices of the stitch-formingl mechanism and less wear upon and weakenl ing of the thread. c When a supply of thread is introduced 1nto the thread-holder the end of this thread must be threaded through a tension device and a sufficient length ,of thread drawnv ott' from the thread supply to reach zit-he work and be sewed into t-he seam, and certain fea' tures of the invention contempla-te the employment of devices for automatically performing these operations, v In accordance with the broaderfeatures of the invention the means for passing a loop of the needle thread Iabcutfthe holder which carries the thread supply `from which the locking thread is drawn. may be of any suitable or Wellknown constructionyandthe passingof the loop of needle thread aboutv the holder maybe effected by a movement of either t-heloop of thread o-r of the threadA holder or of both.

thread supply into the holderinay a'lsofbe` effected inany suitable manner althouglrit" is preferred to carry the thread' supplyupoir )The introduction 'of 'the i athread bobbin and to' replenish the supply of thread in the empty bobbin from the holder and replacing vit with a full bobbin.`

-In embody-ing the broader features' of the holder by removinggan' Y `invention in a concrete construction Iv have f devised certain further features of inve'n#v tion which, while-they 'are-not` essential` to areof the broader features of the'invention,

importance in contributing to tl'iesi'mplicity and elhciency of the machine.V

` The variouseatures ofthe 'invention will Y 1 Y fienfth fel* l1 1 lowing .detailed lde scription', of the construcd be understooodr from an inspectior'iA of the accompanyingy 'drawings and tion shown therein.v `1

In these draWingsgfFigurel isaffront elei vation of a part of a sewing machine emsive steps in the operation of changing' the ion 7 .fixed to the shank and meshing with .shaft which carries the 'pinion (Figs.

thread bobbin and arranged in line with the openings through the rear of the bobbin .hol er and shuttle. This recess 16 is provided with lateral openin s 17and 18 constituting respectively an out etthrough which empty 7c obbins may be discharge and an inlet through which full bobbins may be introduced bodying the features of the present invention iii their preferred forni; ig. 2 is a plan view; Fig. 3 is a sectional elevation through the axis of the shuttle, looking from right to left; Fig. 4 is a similar view showing in detail and partly in scctilon the startin(y and sto iii(r mechanism- 1in. 5 is a deiztiil front vpilejw lbf the shuttle,andid` pito tie recess 16. When a bobbin is to be jacent parts; Fig. 6 is a detail plan view of introduced into the bobbin holder, the rotatlie bobbin case and tension device; Figs. i. `tion, of the shuttle and driver is arrested 7d i iwiththe opening 18 in register with the lower end of a'vertical chute`19 in which a series of full bobbins are supported. The series of bobbins iii the chute .19 are'normally supported upon a gate 21. Wheira bobgo bobbin; Fig. 10 is a detail planview (if the bobbin feeding gates and their actuating drawn from the chute and at the same time a second gate 22 is moved forward between the lower bobbin a'nd the next bobbin in the chute so that the lower bobbin is separated from the series of bobbins in the chute and allowed to drop into the recess 16.

e insertion of the bobbins into the bob bin holder and the removal of the emptied bobbins therefrom isA effected by a plunger 23 mounted concentrically in the shank of te shuttle driver as indicated in Fig. 3.

en a bobbin is to be introduced the plun ger 23 is retracted so that the bobbin may be dropped from the chiite 19 into the recess 95 in front of the plunger. The lunger then advances carrying the bobbin orward into the bobbin holder. In order that the `plunger may also act to remove an emptied bo bin when it is ejected from the bobbin holder, the plunger is forked at its forward end so as to provide two resilient prongs 24 .which are bent slightly away from each other and are beveled at 25 on t eir forward extremities. When an emptied bobbin is to be removed the plunger is advanced to bring the bevel ends 25 of the prongs into the opening in the 'center vof the bobbin and then the bobbin is forced out of the bobbin holder and on to the end -o-f the p unger. The plunger is then relhe emptied bobbin with it until the bobbin strikes against the rear end of the recess 16 when the continued movement of the plunger withdraws it from` the'bobbin so that the bobbin mayv drop through the opening 17.

.fter a full bobbin has been inserted in l. the bobbin holder it is necessary to draw the y cndof the thread carried by the bobbin into usual or suitable form. Y

In t e machine shown in the drawings the means `for passing aloop of needle thread about the locking thread supply is a rotary discoidal shuttle and the locking thread supply is replenished whenl exhausted by removing an emptied thread bobbin therefor, these operations being performed automatically under the control of The shuttle indicated at 1 is mounted to rotate in a shuttle race or casing 2 and is actuated by projections 3 on the rotating' shuttle driver 4'. Theshank 5 of the shuttle driver is journaled in a bearing 6 and the shuttle driver is rotated through a pina pinion 8. The pinion 8 is secured to a shaft which is driven from the driving shaft 1l of the machine by a bevel gear 10 fixed to the driving shaft and engaging a bevel' pinion 9 secured to the end'of the 2 and 3.)

The Vshuttle is provided with a concentric recess within which a bobbin holder 13 is oosely mounted so that the shuttle may rotate freely about the holder which is held 'rom rotation by devices to be hereinafter described. The bobbin holder is provided with a concentric stud 14 upon which the nose 27 projecting from the front face of the bobbin hol er as shown in Figs. 5 and 6. 125

he other member of the tension device n consists of a tension spring, the lower end 28 the bobbin holder within the shuttle.` The of whichv is arranged to engage the thread shuttle driver is provided with a recess 16 and press it against the nose 27. This equal invdiameter to the diameter of the spring is provided with a curved shank 29 130 which fits within a recess formed in the pe- -against the thread may be adjusted by a screw 33 which engages the endof the shank 29 and by which the spring may be moved circumferentially' on the bobbin holder. This arrangement and construction of the tension device enables the thread to be inserted vtherein by a simple forward and downward movement and with or without the assistance of a device arranged to enter between the thread nose and tension spring to separate them as the thread.is introduced.

The bohbin holder Vis held from rotation during the operation of the machine by a retaining device which embraces the thread nose 27 and tension spring 28. This retainer is mounted upon an arm 36 which also carries a device 37 arranged to enter hetween the members of the tension device and separate them when the end of the bobbin thread is to be carried between said members. (Fig. 5). y

In case the4 end of the bobbin thread is to he drawn into the tension device by automatic devices, it should' be presented in the same position whenever a full bobbin is introduced into the bobbin holder. To insure the proper positioning of the end of the hobbin thread, the forward flange 38 of the bobbin is provided with recesses forming vertical shoulders 39 (Fig. 5) and the chute 19 is provided with vertical guides 40 (Figs. 2 and l10) arranged to engage the shoulders, so that each bobhin is delivered into the recess 16 in the shuttle driver in the same relative position. is inserted at the time of filling the bobbin in a notch 41 formed in the flange 38 of the bobbin. his notch is made narrow enough to hold the thread securelyand about 1/16th of an inch of the thread is allowed to project frcm the notch to permit the seizin of the end of the thread bythe thread pul ing 'grippe-rs to be described. A vertical groove 42 (Fig. 2) is formed in the chute 19t-o accommodate this projecting end of the bobbm thread. A

When the bobbin is' lntroduced Vinto the bobbin,holder the end of the thread projecting lfrom the .notch 41 is presented in positien to be engaged and seized by the jaws of a thread puller 43. Thisvthrcad puller comprises two arms 44 and y45 which are pivoted together at46, the lower end of the arm 44 forming the Vfixed jaw.l of the gripper end the lower end ofthe arm 45 forming' the movable 'jaw of the gripper. These lower gripping ends of the arms 44 and 45 vare The end of the bcbbin thread formed as slender curved fingers 48 which are adapted to enter an opening 49 in the fae of the bobbin holder and seize the end of the bobbin thread between them. The arm 44 of the thread puller is mounted on a shaft 17 (Fig. 1) which is rocked at proper intervals to move the lower end of the arms 44 and 45 toward or away from the bobbin holder.

The arm 86 which carries the' bobbin holder 35 and the tension opener 37, and alsothe shaft 47 which carries the thread puller, are mounted upon a sleeve which is arranged to slide vertically on the bobhin chute 19 and whichis operated by mechanism to be descrihed'to impart vertical movements to the thread puller device,4 t0. the retainer for the bobbin holder, and to the ytension opener.

When the supply of thread within the bobbin holder is to be replenished the machine is stopped with the shuttle driver in 1 a position indicated in Fig. 3 and the mechanism which .operates the devices for removing and inserting the bebbins and for pass ing the bobbin thread through the tension A device and drawing off the proper length of thread is thrown into operation by the operator. l/Vhen this mechanism is thus set into operation the plunger 23 is advanced to the position indicated in Fig. 7 and the fingers 48 of the thread puller are at the same time advanced so that they engage the front of the empty bobbin and push it back, upon the prongs of the plunger as indicated in saidV figure. rI`he plunger then retreats to its extreme rearward position so as to carry the empty bobbin against the rear end of the recess 16 and to withdraw from the bobbin which falls through the outlet opening 17. After the empty bobbin has vpassed from beneath the opening 18 at the bottom of the feed chute 19, the gates 21 and 22 act to deliver a full hobbin through the openingr 18 into the recess 16 and in front of the vretracted plungerA Q3. The plunger then moves 'forward again and pushes the full bobbin into the bobbin holder while the fingers 48 of the thread puller move a' short downward movement is imparted to the fingers to free the thread from the no tch 41. The thread gripping fingers then move downward and outward toy carry the thread between the members of the tension device.

vAt the same time the tension opener 37 is advanced between the thread nose and the tension spring above' the threadand f ads them apart so that the tension d' s not resistthe free movement. o under the pull exerted by the thret parted to' the bobbin .52 fixed 'An outward movement is then given to the to draw out slack thread as thread pullerenongh thread shown in Figy to provide to extend to the Work and start the seam. During this last movement of the thread puller the rounded lower extremity of the tension opener 37 acts f a guide or fulcrum about which the thread is drawn. The gripping fingers of the thread puiler then release the end ofv turns to its original position. At the' same he tension opener 'indicated in Fig.

fr the hobbit holder also returns to normal position Where.

it embraces the thread nose 27 and tension spring 28 and prevents rotation of the bobbin holder. The plunger23 'also retreats slightly to clear the shuttle.

he movements above described are irnehanging device bf a ygroup of cams indicated generally by the reference character 51. These cams are secured together and are journaled on a sleeve the4 shaft 11 is mounted, and forming a bearing for the shaft, so that the cains 51 are mounted concentrically with but independently of the Shaft.-

The sleeve 55 on which the thread puller, the' retainer .for the bobbin holder, and the tension opener are carried., is moved vertiengaged by an cally to give the required vertieal movements to these parts by a cam groove formed in the face of the gear 64 through which the camgroup 51 is driven. This cam groove is engaged by a cam roller 63 carried by an arm 62 which is secured to a rock shaft 59. The rock shaft is journaled at one end in a portion of' the framex which is omitted from the drawings, and at. the other end in a bracket (i1 on the upright 53. An arm 58 is secured to this rock shaft, and is provided at its outer end with an adjustable pin 57 which engages tivo lugs 56 formed on the rear side of the sleeve 55.

The inward and outward swinging movements of the thread puller arms 44 and -45 are produced by a cam in the cam group 51. This cam is engaged by an arm 69 fixed to one end of a sleeve 68 which is journaled on the shaft 59 (Fig. 2 second arm 67 is fixed to the opposite end of the sleeve GS, and is connected by a link 66 with an arm 65 which is secured to the shaft 47 which carries the thread puller arms. A 'spring 71 surrounding the link 66 and engaging a lug 72 on the slide sleeve 55 keeps the arm 59 in contact with the cam 70.

The opening and closing of .fingers of the thread puller are effected by a cam S3 ofthe cam group 5,1. This camis arm 82 secured to one' end of The other end 75 of this lever upper end of the arm 45 of the thread puller.

the thread and the puller re-v in one of the uprights 53 in whichV ,and 102. pin 103 the gripper.

a sleeve 81 which is 68 above referred to (l'figs. 2-and second arm journaled on the sleeve is secured to the other end of' the sleeve 81, and is connected by a link 79 with one arm 78 of a .lever oted 76 to a lug 77 on the slide sleeve 55.

grasshopper spring 73 is mounted between the arms 44 and 4 5 of the thread puller, and tenda todhold 'the gripping fingers 4S of the thread puller together.

- The plunger 23 is fixed to a slide-85 which is guided in machine, and this slide is operated to impart the pre-per longitudinal movements to the plunger by e. cam groove 95 formed in the side of the above referred to. The slide 85 is provided with a roller S7 which is engaged by the forked end of an arm 88 which is offset at 89 (Fig. 10) and is fixed to one end of the sleeve 90 journaled on the sleeve 81 above referred to. A second arm 91 is fixed to the other end of the sleeve, and is pivoted to a link 92. The link is provided With a looped extremity 93 formed to slide on the sleeve 52and is provided with a cam roll 94 which engages the cam path 95.

The gates 21 Aand 22 which act to separate individual bobbins from the series of bobbins in the chute 19, and deliver them in front of the plunger 23, are advanced (Figs. 1 and 10) which is mounted to move between the outer ends of the gates, and is provided With inclined cani slots 101 The carn'slot 101 is engaged by a projecting from the gate 22, while the cam slot .102 is engaged by a pin 103 projecting from .the gate 21.

the movements` of arm 88 which operates the plunger 23. The slide isconn-ected to the arm 88 by means of ya link 104, one end of which is connected With the slide, and the other end of which is pivoted to the arm-88 at 105. The cam slots 101 and 102 are so'arranged that when the plunger 23 is moved backward the cam slots act to advance th act to move the gates 1n the reverse'direcadvancing the gate 21 and ret-racting the gate 22./so that the lowermost bobbin is supported upon the gate 21 in position to be released upon the next operation of the The forward ends f the gates may be bcvcledas indicated at 106 (Fig. 10) to facilitate their entrance bet-Ween the bobbins.

ln the construction shoxvn,- the stitch forming mechanism and the mechanism for which is pivengages thev Ways 86 on the frame of the.

and retracted at proper intervals by a slide lio ` same driver, whichmay 'be connected either Awith'the stitch forming mechanism or with 'the j mechanism for Vreplenishing the thread "supply 'at the will of theoperator.

As shown, the driverconsists of a pulley 109 provided with a driving plate 110. The vpulley and driving plate are journaledpto turn freelyv upon a sleeve 107 which is fixed tothe end of the main shaft 11 of the mach'inegand forms an extension of said shaft. The sleeve 107 is, provided with a frict-ion Vplate 111 arranged upon one side of the driving Aplate Y110 and adapted to be friction'ally Iengaged and driven thereby.` A

vsecond friction'pl'atev112 isfarranged on the lopposite sidey of the driving plate 110, and,

is loosely 'journaled'upon the projecting end 113,of the sleeve 52 on which the group Aof cams 51 which operate the threadl replenishing `mechanism is mounted.A A vpinion'114t is fixed to ythe'ihulo of the plate cured v-'onone end to'a- 'shaft 116 journaled inthe column-53. Afpinion 117V is fixed to the other end of fthe shaft 116, and engages the gear 64 which is connected with and forms a 'part'J of .the cam group 51. 1V lienth'e drivingplate 110 is in engagementii'ith'the" friction plate 112 it operatesv tofrictionallyfdrive the plate 112 1and through 'it and the connecting gear todri-ve )o"sitionlagainst the 'tension ofthe spring" tends'to fo-rcethe pulley toward the left in Fig. 1,' and to`rnaintain the driving'pl'ate 110 in frict-i'ona'l engagement with the friction lplate 111. The pulley and driving plate'vare lmoved 'and heldv against the tension'pof the spring 122 `by. means of a rod"119'wh1ch'sl1des in a central recess 1n fthe main shaft 11, *and is provided with fixed collars arranged to engage opposite sides of a plate Y121 fixed to the end of the Ahuh l1081 of the pulley." :The longitudinal movements* of the v'rod 11S) which result in .the engagement ofthe driving plate 110 with either of the frictien plates 111 or 112, or themevement of said driving plateinto mid-position between said v frictionv iplatcs, are' controlled for.v effected yby a forked vwed ge 127 arranged between a. collar `123gwhich isyccnnected-with the rod '119, andan in-'- clinedfcollar120 'whicl1 is formed on the end .of the sleeve-52 (Figs. 1=Land 2)'. The collar 123 is mounted on the shaft 11, and

f `is connected with ythe1rod 119 by`mea`ns of a cross-'pin ,124. which" passes -throughxthe eollarrland rod' and 'tliroughslcts'v 125 in' and engages aI gear .115 which is se? the shaft 11. When the forked wedge 127 is in the position indicated in Fig. 1 it maintains vt-he pulley and driving plate in mid-position so that neither the sewing' mechanism nor the thread replenishing mechanism is operated. The forked wedge is fixed to the upper. end of a rod 128, and is maintained in the position indicated in Fig. 1 by an arm 129 which projects rearwardly from ar sleeve 130 and supports the lower end of the rod. The sleeve 130 is loosely journaled on a rock shaft 131.which is mounted in lugs 132 in the frame yof the machine, and this sleeve is provided with a lug 133 adapted to engage a corresponding lug on a sleeve 134 which is fixed on the rock shaft. The rock shaft is normally vmaintained in the posit-ion indicated in Fig.

1 by the `action of a spring 13S acting upon a treadle 137 which is connected by means of .a link 136 with an arm 135 secured to the rock shaft (Eig. 4). The spring acts to hold the treadle against a stop 137, and to thus maintain the shaft 131 in the position indicated. rVith the shaft in this position, the lug 133 `on the sleeve 130 engages the lug 13,4 and supports the arm 129 inthe position indicated, so that the forked wed-ge 127 is heldin proper position between the collars 123 and 126 to maintain the driving plate 110 midway between driving plate 110 with the friction plate 111 lthus connecting the driver with the sewing mechanism. The sewing mechanism will continue in operation so long as the treadle 137 is depressed. W'hen the treadle is released the spring 138 will return the treadle.

to its upward position against the stop 137a thus rocking the shaft 131 and operating the sleeve 130 and arm 128 to raise the wedge v127to the position indicated in Fig. 1. This movement of the wedge shifts the'driving driving plate 110 into `engagement with the friction disk 112. i' vThis movement ofthev wedge 127 is e'ectedby a treadle 145 which is connected .by means of` a 'link 141 to an the yshaft V131. ed`4 a lug l 141.gif:

.arm 143 project-ingfrom a sleeve'140which i is loosely mounted'on Ysleeve proY ranged to engage a similar lug on the sleeve 130 which carries the arm 129 for supporting the wedge. When the treadle 145 is depressed the sleeve 140 is rockedand the lug 141 on the sleeve engages the lug on the sleeve 130 rocking this sleeve and raising the arm 139 so that the wedged 27 isforced between the collars 126 and 123. The movement thus imparted to the collar 123 causes ed ov means of y A order that the the driving the driver 110 to 'be engaged with the friction disk 112 so that the bc-bbin changing mechanism is thrown into operation. The operationof the bobbin changing mechanism will continue until the wedge 127 is returned to the normal position indicated in Fig. 1, when the spring 122 will shift the driving plate 110 into mid-position. `When the bobbin changing-mechanism is connected with the driver, the connection should continue until the cycle of o erations incident to the change of the bob in has been completed and then vthe mechanism'shou'ld be disconnected from the driving mechanism. In bobbin changing mechanism may remain connected with the driving mechanism after it has once been connected therewith ,by the operator, until the changing of the bobbins has beeneifected and may then be disconnected from the driving mechanism without requiring the attention of the provided for automati operator, means' are cally performing these op'erations. In the construction shown, the connection betweenk mechanism `and the bobbmv changing mechanism is maintained b y means ofa pawl 147 arranged'to engage teeth 146 formed on the' trolling Wedge 127 is secured and to retain the rod and wedge in their raised position when the wedge 1s raised by the depression of the treadle 145. ,The pawl yieldingly toward the rod 128 hy a spring 148 and the rear end of the pawl is connecta link 149 with a pin 150 mounted on the arm 6,2 through which the slide sleeve is operated. The pin 150 plays in an elongated slotin the, upper end of the link 149 so that a certain amount oi lost motion between the link 149 and the The cam groove to the arm 62 is bobbin changing arm 62 is provided for.V which imparts movements so shaped that when the mechanism is thrown .into operation, a slight upward movement is imparted to the arm 62 which carries the pin 150 away from the lower end of the slot in the link 149 allowing the pawl 147 to swing over into engagement .with the teeth 146 on the rod 128. The pawl now retains the rod 1 28 and wedge 127 in raised position until the group of cams 51 which operate the devices of the bobbin c ianging'mechanism have made a complete revolution, when the arm 62 is returned to the` position indicated in Fig. 1. This moverod 128 to which the con# 147 is forced cylinder link is Low/,oise

ment of the arm brings the pin 150 against the lower end of the slot in the link 149, thus rocking the pawlv 147 out of engagement with the teeth 146 on the rod 128, so that the rod and wedge 127 lnay fall-into the position indicated 1n Fig. 1.. When the Wedge returns to this 122 acts to disengage the driving plate v110 from the :friction plate 112, thus disconnecting the bobbin changing mechanism from thedriving mechanism.

has already been explained the sewing mechanism when thrown out of operation should be arrested in such position that the opening 18 through which the bobbins are introduced into the recess in the bobbin driver shall be in register with the lower end of the feed chute 19. In order that the sewing mechanism maybe stopped in this position, an automatic sto-p mechanism is provided. In the construction shown this stop mechanism comprises a spring buffer adapted to be movedv into the path of a lug or projection carried by the treadle 137 is operated to disconnect the driving mechanism and sewing mechanism. As shown in Figs. 1 and 4, one of the cams 152 which is secured to the shaft 11 is rovided with a stop lug 153. The spring uffer which is-adapted to engage this lug comprises a cylinder 154 pivot-ally lnounted a't- 151 on the frame. A plunger 155 slides in the cylinder and has a head adapted to enposition the spring gage thestop lug. A collar 157 on the plunger 1s engaged by a stili spring 158 in the cylindern. The plunger extends through a gland 159 and is provided with a piston 160 sliding in a cylinder 161. The piston is provided with vents 162 controlled by check valves 163. Gl

put into the cylinder to the operation of. the piston may move freely downward while its upward movement is retarded` by the fluid. A tensionspring 164 connecting the 154 and the frame-of the machine into position be- 161 and owing check valves the tends Vtoswing the buffer neath the stop lug, while the machine is in operation by a detent 165 which engages a lug 166 on the cylinder 154. The detent is rod 167 which slides vertically in the frame of the machine and rests at its lower end on an arm 16S integral with a sleeve 169 fixed en the rock shaft 131. nothcr armA 170 depending from' the sleeve 169 is connected by a. link 171with the butler to which the pivoted at 172'. The detent is provided with a trip arm173 adapted to engage the stop lug 153.

The stop mechanism operates as follows When 4the rock shaft 131 is rotated by depressing the treadle 137 to start the machine, the arm 170 and link 171 swing the plunger down' ycerin or oilV is" but this 1s prevented pivoted on the top of auf?,

it is arrested by the engagement of the de? tent 165 and the lug 166. At the same time the detent isfraised so as to bring the trip army 178 into the path of movement'of the stop lug. lVhen the stop lug engages the trip arm`it thereby disengages the detent and t-he buffer .immediately swings into the path of the stop lug. The latter then engages the buffer and is arrested by the yielding resistance thereof and the sewing mechanism is thus brought to rest immediately but without any jar. The spring then expands gently against the resistance of the glycerin check and moves the stop lug accurately `to a predetermined position.

In operating this machine it is necessary .l only to keep a supply of full bobbins in the chute and to depress the treadle 145 as often as it is necessary to replenish theshuttle thread. The bobbins are preferably wound with an amount of thread justsutlicient to 'sew a definite number of shoes'and the bobbins are therefore changed at regular intervals.

The natureand Object of the invention having beeny set forth, and'one form of mech-v anism in which the features of invention may be embodied having been described, what 1s claimed 1s:-

1. A sewing machlne, having, in combination stitch forming devices including a holder'for the locking thread supply, a bobbin holding magazine, land means for transferring a bobbin from the magazine to the holder, substantially as described.

2. A sewing machine, having in combination stitch forming devices'including ya bobbin holderfor the locking thread supply, means for passing a loop of needle thread about the bobbin holder, a bobbin'holding magazine, and mechanism operating to remove a bobbin from the holder and to transfer a bobbin from the magazine to the holder, substantially as described.

3. A sewing machine, having in combination a bobbin holder for the locking thread supply, means for passing a loop of needle thread about the' bobbin holder, a bobbin holding magazine, and mechanism under the control of the operator for removing a bobbin from the holder and transferring a bobbin from the magazine to the holder, subsltantially as described.

y 4. A sewing machine, having in combina# tion aholder for the'locking threadsupply .open at the rear, a rotary device for passing a loop of needle thread about the holder, and mechanism operating to introduce a supply of thread through the rearof the holder, substantially as described.

5. A sewing machine, having, in combinaticn a holder for the locking thread supply open at the rear, means for engaging and carrying a loop of needle thread around the holder, and mechanism operating to introduce a bobbin through the rear of the holder, substantially as described.

6. A sewing machine, having, in combination stitch forming mechanism including a discoidal shuttle, a bobbin'holder' for the locking thread supply, and mechanism operating to remove an lempty bobbin from the holder4 and replace it with a full bobbin, s ubstantially as described.

7 A sewing machine, having, in combination, a device. for holding a supply of thread, means for passing a loop of needle thread about the holder, mechanism constructed and arranged to introduce a segregated 'supply of thread into the holder, and means.

constructed and arranged'to seize anddraw out the free end of said thread, substantially as described.

8. A sew-ing machine, having, in combination, stitch forming mechanism including a device for holding a supplyof thread, a tenH sion device, mechanism constructed and arranged to introduce a segregated supply of thread into the holding device with the free end in a predetermined position, and mecha.

nism for threading the thread through the tension device, substantially as described.

9. A sewing machine, having, in combination, a ,bobbin holder, means for passing a loop of needle thread about the holder, a

bobbin changing mechanism for changing the bobbin within the holder, and means' for seizing the free end vrof the thread extending from the bobbin and drawing it out of the holder, substantially as described.

10. A sewing machine, having, in c ombination,a bobbin holder, means for passing a loop of needle thread about the holder, a

bobbin changing mechanism for changing the bobbin within the holder, a tension de vice, and means for seizingthe free endf the thread extending from the bobbin and threading it through the tension device, subs'tantially as described.

11. A sewing machine, having in combination a device for holding a supply of thread, means for passing a loop of thread about the holding device., and means. for seizing the end of the thread supply and drawing it out of the holder, substantially as described.

12. A sewing machine, having, in combination stitch forming mechanism including a shuttle, mechanism for replenishing the fsupply of threztd', in the shuttle, shuttle drivf 

